1. Field of the Invention
The present invention relates to a coating apparatus and a method for real-timely monitoring thickness change of a coating film and, more particularly, to a coating apparatus and a method for real-timely monitoring thickness change of an organic coating film.
2. Description of Related Art
As the semiconductor technology and the industry of liquid crystal display devices develop upward, a coating process has been widely used in the domestic and foreign industries. Currently, the domestic and foreign industries are using post-production examination of a coating film. In other words, the measurement for the thickness of the coating film can only be performed after the coating process has finished and the coated sample is taken out. The quality of the resultant coating film can be recognized only after the abovementioned measurement, but not in the real-time course of the coating process. Of course, this leads to an undesirable scrapping of products when there has been a flaw in the manufacturing process. Therefore, post-production examination is not helpful to the yield of the coating process.
Previously, contact-type examination was reported. However, this type of examination still belongs to post-production examination and the coating film may be easily damaged during such. Besides, inspection using an optical system was reported. Nevertheless, such inspection is limited to a material of a substrate coated in the coating process and also can not achieve the real-time examination. Furthermore, an optical monitor system was reported, but such monitor system is limited in the precision of optical component arrangement and in the volume of the system. Thus, it is not convenient for the application of this system. In addition to the abovementioned, a piezoelectric detection technology of quartz crystal microbalance (QCM) was reported. Although this technology seems to realize the real-time monitoring, the detection system and components cannot be used in a vacuum chamber, and thus real-time monitoring for a coating film still cannot be accomplished in a mass production at present.
The aforesaid technologies mostly are applied in thickness detection of an inorganic coating film. Nonetheless, referring to thickness detection of an organic coating film, there is no useful technology presently. If the detection reaches to nano-scale detection of a film thickness, the detection system is expensive.
In view of the mentioned above, if a technology to detect nano-scale thickness of a coating film and the technology can achieve real-time monitoring, loss reduction of failed processes, deposition monitoring of an organic film, simple operation, and low costs, it will be beneficial for the development of semiconductor-related technologies.